Hi ,
I'm trying to scale up, but the only rotor I found in the facility is way too large (which fits 50 mL ultracentrifugal tubes, and I already had these)for my maximal yield (which is 15-20 mL). I need exactly 40,000g (yes, high speed one) for optimal product recovery, which had been well-established in small scale : 1 mL ultracetritubes.
Is there any equation for correcting the RCF? Any advice/feedback is welcome.
*the adaptor for 10 mL ultracentrifugal tubes is not available in my region.
** 50 mL is smallest rotor of the machine. The other one is 500mL.
You have to measure rotor radius (in this case, the distance from the point of the sample closest to the axis of the centrifuge to the axis itself) in mm. Then the rpm necessary to produce at least 40,000 x g will be 1000*SQRT(40,000(1.12*r)).
In theory you should also change the length of the centrifugation (as the distance the analyte will have to travel to the bottom of the tube most likely has changed as well) but in this case it probably does not matter.
Hope it helps!
Hi Alejandro,
Thank you for your info. Actually, the length for analytes traveling to the bottom, as you mentioned, is quite influential as far as the recovery rate of the nanoparticles concerned in my exp. I end up using K factor for it corrects both RCF and TIME which depends on the fluid levels in different tubes, and I found K factor useful not only in the case of inconsistent centrifuges but when the RCFmax is not enough for a well-established protocol and requires more time to compensate, although it does take significantly much more time.
k=ln(Rmax/Rmin)/S2*2.533*1011 ; Time 2 = Time 1* (K2/K1)
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